*Purpose: Islet transplantation is a thriving therapy for patients with Chronic Pancreatitis and Type-1 Diabetes. Within the pancreas, the islets are surrounded by Extracellular Matrix (ECM) proteins and interaction of islets with ECM has been shown to regulate essential function. Isolation of islets results in destruction of islet-ECM network that may play an important role in islet survival, proliferation, and insulin secretion. The purpose of this study is to evaluate the role of pancreas derived ECM on islet function and viability during in vitro culture.

*Methods: Islets and ECM were isolated using modified Ricordi’s protocol from pancreas obtained from cadaveric donors for research purpose. Remnant pancreas connective tissue was harvested after complete digestion. Residual cells were lysed and connective tissue was further digested with pepsin, lyophilized and milled into powder. The powdered ECM was reconstituted in buffer solution. We coated the plates with ECM (0.1, 1, 10, or 100 ug/ml, respectively) for culturing human islets for 48hrs. Islets were then tested for viability and glucose stimulated insulin secretion (GSIS) function. The stimulation index was calculated by dividing the insulin concentration in the high glucose solution (16.7 mM) by that in the low glucose solution (1.67 mM). Viability was determined by staining the islets with Hoechst and Propidium Iodide and percentage viability was visually determined for n=10 islets/group. Protein analysis of ECM fraction was also performed.

*Results: Co-culture of islets with ECM had no significant effect on the viability of islets at the concentrations tested. A significant difference in stimulation index was found between the control and ECM at concentration of 100 ug/ml (4.3±1.3 vs. 6.5±1.2; p < 0.05). Protein analysis revealed the presence of fibronectin in the ECM fraction. Scanning electron microscopy revealed presence of collagen fibers even after isolation and decellularization.

*Conclusions: Co-culture of islets with pancreatic ECM did not affect the viability, however there was a significant increase in the insulin release in response to glucose. ECM from pancreas has the potential to be used as material for encapsulation or coating for islet culture before transplantation.

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